Journal List > Diabetes Metab J > v.41(1) > 1084999

Yun and Ko: Response: Clinical Course and Risk Factors of Diabetic Retinopathy in Patients with Type 2 Diabetes Mellitus in Korea (Diabetes Metab J 2016;40:482-93)
We sincerely appreciate the interests and comments on our study, “Clinical course and risk factors of diabetic retinopathy in patients with type 2 diabetes mellitus in Korea” which was published in Diabetes & Metabolism Journal.
Establishing the clinical course and risk factors of diabetic retinopathy (DR) is important to prevent blindness and improve a quality of life of diabetes patients [1]. Based on the results of this study, we suggested that the glycemic control, diabetes duration, age, and albuminuria are the significant predictive factors of the development of DR [2]. Furthermore, among them, glycemic control is the most important modifiable factor, even in the patients with a long duration of diabetes.
Previous epidemiologic studies on the development and progression of DR have been suggested [345]. As Dr. Kim mentioned in his letter, the prevalence of DR in the early stage of diabetes of our cohort differed from that of UK Prospective Diabetes Study (UKPDS) and Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR) [67]. In our hospital-based cohort, among total 1,486 patients who were enrolled and received screening test of DR from 2000 to 2006, 387 patients (26.5%) had DR initially. Of the 496 patients who were newly diagnosed with type 2 diabetes mellitus, only 31 patients (8.3%) had DR at the time of diabetes diagnosis. The prevalence of DR in our cohort was lower than those of WESDR (28.8% less than 5 years) and UKPDS (37% at diagnosis of diabetes). This difference could result from the different characteristics of enrolled study population and study design between the studies. Our study designed to confirm the clinical course and establish predictive factors of DR in the patients at risk for developing DR. The mean diabetes duration was 6.7 years, and many patients who developed DR within 5 years from the diagnosis of diabetes could be excluded in this study. More generalized screening for diabetes and better care of the metabolic conditions of diabetes in our cohort compared with previous study could be another factor related with the delayed progression of DR.
The recent Action to Control Cardiovascular Risk in Diabetes Follow-On (ACCORDION) Eye Study suggested that intensive blood pressure control had no effect on the clinical course of DR [8]. Although some previous studies including UKPDS demonstrated that intensive blood pressure control delayed the progression of DR significantly [9], the proper blood pressure target for DR is still inconclusive. For this reason, when we conducted statistical analysis, the presence of hypertension at enrollment was adjusted; however, we could not reflect the blood pressure change of each subject during the whole follow-up period. We have a plan to analyze the association between metabolic profiles and DR reflecting the longitudinal data such as regular checked glycosylated hemoglobin, blood pressure, or lipid level during the study using a linear mixed model in the near future.
We would like to express our sincere gratitude to Dr. Kim for the interest in our study and the thoughtful comments.


CONFLICTS OF INTEREST No potential conflict of interest relevant to this article was reported.


1. Cheung N, Mitchell P, Wong TY. Diabetic retinopathy. Lancet. 2010; 376:124–136.
2. Yun JS, Lim TS, Cha SA, Ahn YB, Song KH, Choi JA, Kwon J, Jee D, Cho YK, Park YM, Ko SH. Clinical course and risk factors of diabetic retinopathy in patients with type 2 diabetes mellitus in Korea. Diabetes Metab J. 2016; 40:482–493.
3. Jones CD, Greenwood RH, Misra A, Bachmann MO. Incidence and progression of diabetic retinopathy during 17 years of a population-based screening program in England. Diabetes Care. 2012; 35:592–596.
4. Martin-Merino E, Fortuny J, Rivero-Ferrer E, Garcia-Rodriguez LA. Incidence of retinal complications in a cohort of newly diagnosed diabetic patients. PLoS One. 2014; 9:e100283.
5. Kawasaki R, Tanaka S, Tanaka S, Abe S, Sone H, Yokote K, Ishibashi S, Katayama S, Ohashi Y, Akanuma Y, Yamada N, Yamashita H. Japan Diabetes Complications Study Group. Risk of cardiovascular diseases is increased even with mild diabetic retinopathy: the Japan Diabetes Complications Study. Ophthalmology. 2013; 120:574–582.
6. Stratton IM, Kohner EM, Aldington SJ, Turner RC, Holman RR, Manley SE, Matthews DR. UKPDS 50: risk factors for incidence and progression of retinopathy in type II diabetes over 6 years from diagnosis. Diabetologia. 2001; 44:156–163.
7. Klein R, Klein BE, Moss SE, Davis MD, DeMets DL. The Wisconsin epidemiologic study of diabetic retinopathy. III. Prevalence and risk of diabetic retinopathy when age at diagnosis is 30 or more years. Arch Ophthalmol. 1984; 102:527–532.
8. Action to Control Cardiovascular Risk in Diabetes Follow-On (ACCORDION) Eye Study Group and the Action to Control Cardiovascular Risk in Diabetes Follow-On (ACCORDION) Study Group. Persistent effects of intensive glycemic control on retinopathy in type 2 diabetes in the action to control cardiovascular risk in diabetes (ACCORD) follow-on study. Diabetes Care. 2016; 39:1089–1100.
9. UK Prospective Diabetes Study Group. Tight blood pressure control and risk of macrovascular and microvascular complications in type 2 diabetes: UKPDS 38. BMJ. 1998; 317:703–713.

Seung-Hyun Ko

Similar articles